Compound (I) represented by the following structural formula:
is disclosed in U.S. Pat. No. 8,524,918, and has an excellent efficacy as a mineralocorticoid receptor (MR) (aldosterone receptor) antagonist, and therefore is expected to have an excellent therapeutic effect and/or preventive effect on a disease such as hypertension, a heart disease [ angina pectoris, myocardial infarction, cardiac arrhythmia (including sudden death), heart failure, or cardiac hypertrophy], a kidney disease (diabetic nephropathy, glomerulonephritis, or nephrosclerosis), a cerebrovascular disease (cerebral infarction or intracranial hemorrhage) or a vascular disorder (arteriosclerosis, restenosis after PTCA, or peripheral circulatory disturbance). Further, an effect on the amelioration of diabetic nephropathy is also expected.
One of the important conditions for the manufacturing of a pharmaceutical product is that the quality (for example, content, tablet hardness, dissolution property, and disintegration property) thereof is maintained from when the product is manufactured to when the product is taken by a patient, for example, in the course of storage in a warehouse, shipping, and storage in a hospital, a pharmacy, or a home, and so on, and high storage stability over a long period of time is required.